The use of human tissues is central to the projects of this Program Project Grant. Core Unit A provides a central mechanism for both the acquisition and processing of human tissues to meet the experimental needs of the various projects. It has two major components. The first is the acquisition of human tissues, either fresh tissues from Parkland Hospital or frozen samples from the tissue repository. Tissues are obtained both for immediate use by the investigators and for addition to a large tissue repository from which investigators may draw samples as needed. The second component is to provide intrauterine pressure monitoring for experimental animal models. For centuries, obstetricians have attempted to answer the fundamental question as to when labor begins. The development of this sensor will bring about new technology to study this question and will be invaluable to begin to dissect the temporal relationships between the molecular events that occur in maternal and fetal tissues before and during cervical ripening, uterine contractions, and delivery. This substantial enterprise is directed by Dr. Ann Word, P.I., who makes decisions regarding tissue requests, supervises personnel, interacts with clinical services and Pathology, and participates directly in the dissection of certain samples. An organizational chart and detailed description are given below in 'Core A'. A consortium arrangement with Sandia National Laboratories provides a unique partnership in the development of intrauterine pressure sensors, acquisition of data, and analysis as described herein. Core Unit B provides a centralized administrative area to support a variety of administrative tasks associated with the Program Project. The Administrative Core is under the direction ofthe Program Director, Dr. Carole Mendelson. Details are provided in 'Core B'.